Create annotations directly from toolbar tools

[mattdawkins]

Summary

The annotation toolbar can now start an annotation without first pressing + Detection or + Track. With no track selected, choosing Rectangle, Polygon, Line, or Segmentation creates an annotation using the current Detection/Track settings and enters the chosen tool. With a track selected, the same buttons switch its edit mode.

• Add a small + indicator and creation labels when nothing is selected, in both toolbar layouts.
• Enable Text Query without a selected track, keeping its query workflow free of empty placeholder annotations.
• Apply read-only, multi-select, group, lasso, and linking restrictions to toolbar controls and shortcuts.
• Wait for segmentation initialization before creating an annotation; canceling an empty annotation removes it.

Validation

• 50 tests passed across EditorMenu and useModeManager, including creation, tool switching, Detection/Track settings, cancellation, restricted modes, Text Query, and delayed segmentation initialization.
• ESLint on changed files and client TypeScript checks passed.
• Production web build passed.

[BryonLewis]

I think this is fine. I've only made a modification so the buttons don't enable while the lasso tool is calculating the selected tracks.